In Yggdra Union, this element was almost exclusive to the Undine race, as such, they were very susceptible to Fire. Ice, though having no apparent advantage over any other element, was effective against G. Riders and Imperial Knights.
Blizzard is the game's ice-based skill, and although it inflicts no ailment, it does have the special effect to freeze water when an undine uses it.

In Knights in the Nightmare, ice opposed fire. Ice skills were not very effective against lightning or other ice types. The skill of a Hermit could freeze enemies, which completely halted their actions.